drivers/of/device.c

   1 #include <linux/string.h>
   2 #include <linux/kernel.h>
   3 #include <linux/of.h>
   4 #include <linux/of_device.h>
   5 #include <linux/init.h>
   6 #include <linux/module.h>
   7 #include <linux/mod_devicetable.h>
   8 #include <linux/slab.h>
   9
  10 #include <asm/errno.h>
  11 #include "of_private.h"
  12
  13 /**
  14  * of_match_device - Tell if a struct device matches an of_device_id list
  15  * @ids: array of of device match structures to search in
  16  * @dev: the of device structure to match against
  17  *
  18  * Used by a driver to check whether an platform_device present in the
  19  * system is in its list of supported devices.
  20  */
  21 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  22                                            const struct device *dev)
  23 {
  24         if ((!matches) || (!dev->of_node))
  25                 return NULL;
  26         return of_match_node(matches, dev->of_node);
  27 }
  28 EXPORT_SYMBOL(of_match_device);
  29
  30 struct platform_device *of_dev_get(struct platform_device *dev)
  31 {
  32         struct device *tmp;
  33
  34         if (!dev)
  35                 return NULL;
  36         tmp = get_device(&dev->dev);
  37         if (tmp)
  38                 return to_platform_device(tmp);
  39         else
  40                 return NULL;
  41 }
  42 EXPORT_SYMBOL(of_dev_get);
  43
  44 void of_dev_put(struct platform_device *dev)
  45 {
  46         if (dev)
  47                 put_device(&dev->dev);
  48 }
  49 EXPORT_SYMBOL(of_dev_put);
  50
  51 int of_device_add(struct platform_device *ofdev)
  52 {
  53         BUG_ON(ofdev->dev.of_node == NULL);
  54
  55         /* name and id have to be set so that the platform bus doesn't get
  56          * confused on matching */
  57         ofdev->name = dev_name(&ofdev->dev);
  58         ofdev->id = -1;
  59
  60         /* device_add will assume that this device is on the same node as
  61          * the parent. If there is no parent defined, set the node
  62          * explicitly */
  63         if (!ofdev->dev.parent)
  64                 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  65
  66         return device_add(&ofdev->dev);
  67 }
  68
  69 int of_device_register(struct platform_device *pdev)
  70 {
  71         device_initialize(&pdev->dev);
  72         return of_device_add(pdev);
  73 }
  74 EXPORT_SYMBOL(of_device_register);
  75
  76 void of_device_unregister(struct platform_device *ofdev)
  77 {
  78         device_unregister(&ofdev->dev);
  79 }
  80 EXPORT_SYMBOL(of_device_unregister);
  81
  82 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
  83 {
  84         const char *compat;
  85         int cplen, i;
  86         ssize_t tsize, csize, repend;
  87
  88         if ((!dev) || (!dev->of_node))
  89                 return -ENODEV;
  90
  91         /* Name & Type */
  92         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
  93                          dev->of_node->type);
  94
  95         /* Get compatible property if any */
  96         compat = of_get_property(dev->of_node, "compatible", &cplen);
  97         if (!compat)
  98                 return csize;
  99
 100         /* Find true end (we tolerate multiple \0 at the end */
 101         for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
 102                 cplen--;
 103         if (!cplen)
 104                 return csize;
 105         cplen++;
 106
 107         /* Check space (need cplen+1 chars including final \0) */
 108         tsize = csize + cplen;
 109         repend = tsize;
 110
 111         if (csize >= len)               /* @ the limit, all is already filled */
 112                 return tsize;
 113
 114         if (tsize >= len) {             /* limit compat list */
 115                 cplen = len - csize - 1;
 116                 repend = len;
 117         }
 118
 119         /* Copy and do char replacement */
 120         memcpy(&str[csize + 1], compat, cplen);
 121         for (i = csize; i < repend; i++) {
 122                 char c = str[i];
 123                 if (c == '\0')
 124                         str[i] = 'C';
 125                 else if (c == ' ')
 126                         str[i] = '_';
 127         }
 128
 129         return tsize;
 130 }
 131
 132 /**
 133  * of_device_uevent - Display OF related uevent information
 134  */
 135 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 136 {
 137         const char *compat;
 138         struct alias_prop *app;
 139         int seen = 0, cplen, sl;
 140
 141         if ((!dev) || (!dev->of_node))
 142                 return;
 143
 144         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 145         add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
 146         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 147                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 148
 149         /* Since the compatible field can contain pretty much anything
 150          * it's not really legal to split it out with commas. We split it
 151          * up using a number of environment variables instead. */
 152         compat = of_get_property(dev->of_node, "compatible", &cplen);
 153         while (compat && *compat && cplen > 0) {
 154                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 155                 sl = strlen(compat) + 1;
 156                 compat += sl;
 157                 cplen -= sl;
 158                 seen++;
 159         }
 160         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 161
 162         seen = 0;
 163         mutex_lock(&of_aliases_mutex);
 164         list_for_each_entry(app, &aliases_lookup, link) {
 165                 if (dev->of_node == app->np) {
 166                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 167                                        app->alias);
 168                         seen++;
 169                 }
 170         }
 171         mutex_unlock(&of_aliases_mutex);
 172 }
 173
 174 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 175 {
 176         int sl;
 177
 178         if ((!dev) || (!dev->of_node))
 179                 return -ENODEV;
 180
 181         /* Devicetree modalias is tricky, we add it in 2 steps */
 182         if (add_uevent_var(env, "MODALIAS="))
 183                 return -ENOMEM;
 184
 185         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 186                                     sizeof(env->buf) - env->buflen);
 187         if (sl >= (sizeof(env->buf) - env->buflen))
 188                 return -ENOMEM;
 189         env->buflen += sl;
 190
 191         return 0;
 192 }